Critical Psychology investigates human life activity/ consciousness from the "generalized standpoint of the subject". A key concept to grasp the intentional relationship of concrete individuals to the world is the category of 'subjective grounds for action": Objective conditions are not so much direct causes as the circumstances of action. They provide-as cognized meanings-"premises' in the need-related process of an individual's having grounds for his/her intention of acting. This human mode of existence should also determine the form of scientific theorizing: Bearing a certain resemblance to recent interpretations of psychological theories as "implicative linguistic structures", it is maintained that the central components of hypotheses about subjective functionality of acting do not constitute a relationship of empirical contingency, but one of "discursive consistency". As such assumptions do not predict effects, they cannot be considered falsified when they fail to materialize: They simply do not "apply" to cases where the supposed premises are absent. Supporting our perspective of a monistic methodology and metatheory for psychology as a science of the subject, it is pointed out that mainstream psychology's lawful "if-then" statements about human action and subjectivity can be reinterpreted as de facto, albeit implicit and restricted, theories about grounds for action.